We had a stack of different machines, Wirtgens, Roadtecs, CMI's and smaller bobcat attachments as well. All of these machines had different drums to begin with. The bolt on drums were super expensive to run, that's why we went for Schibeci's. I know of a bunch of companies that swear by them... Particularly in tough conditions. We ran with 150, 180 and 220 pic drums. The 220 pic drum did drag a lot, but the texture stayed the same for the whole 2 seasons. I preferred to run the 180 and particularly the 150 drum. The 150 was really quick. I never like hanging around on a job site too long. With the bolt on systems, even the new ones, we could never keep the blocks in for more than 300 hours... We'd always end up welding them in and spending way too much time in the cutter box welding away. So my experience has been pretty good with Schibecis in comparison to other drums. I guess it depends on how tough the conditions are you are working in.